Establishing the Countering Weapons of Mass Destruction (CWMD) office appeared to represent one of Nielsen's first actions since the Senate confirmed her for the role on Tuesday.

Nielsen, a former DHS employee, re-entered the department at a time of mounting tension between the United States and North Korea over the rogue regime's nuclear program. While the United States has attempted to apply diplomatic pressure through economic sanctions, the North Korean regime continued its provocative missile launches and indicated it was unwilling to engage in diplomacy with the United States.